Votes-Seats Distribution

That's a chart I compiled based on the latest 538 projections about the House of Representatives. The x-axis is the Democratic projected margin in that seat, according to the 538 model, while the y-axis is the number of seats Democrats will win if we win all seats where we have at least that good a margin. So at x = 15, you see the number of seats Democrats are currently projected to win by 15 or more points.

Point of interest: (-1, 217), so we need at least one seat we're currently trailing by more than a point in order to keep the gavel in Pelosi's hands.
There are 34 districts within 3 points one way or the other, and 52 districts within 5 points. And 89 within 10 points. A uniform national swing (thanks, England!) of 5 points toward Democrats, and we'd keep 238 seats, better than we had after 2006. A UNS against us of 5 points? 186 seats, a total disaster. That's a pretty big margin with fairly little change in votes.

As always, the swing won't be uniform or national, but it's still a convenient and, I think, somewhat informative way of analyzing everything.